1. ¹Faculty of Biology, University of Belgrade, Belgrade, Serbia
2. ²Department of Evolutionary Biology, Institute for Biological Research 'Sinia Stankovi', Belgrade, Serbia

Correspondence: Dr N Tuci, Department of Evolutionary Biology, Institute for Biological Research 'Sinia Stankovi', Despota Stefana 142, 11060 Belgrade, Serbia. E-mail: ntucic@ibiss.bg.ac.yu

Received 22 June 2006; Revised 6 September 2006; Accepted 23 November 2006; Published online 14 February 2007.

Abstract

We investigated the additive, dominance and epistatic genetic effects underlying differentiation in oviposition preference between two populations of the seed beetle Acanthoscelides obtectus evolved in the laboratory for 102 generations on bean and chickpea seeds. We reared and tested females on each of two host legumes. The populations differed in mean oviposition preference; the preference for chickpea was stronger in population reared on the chickpea (C) than in population maintained on common bean (P). Observations in the parental populations indicated that females tend to prefer ovipositioning their eggs on the seeds they have already experienced. The patterns of the means in each of the parental populations and 12 types of hybrids (two F₁, two F₂ and eight backcrosses) indicated that population differences in oviposition preference from both rearing hosts could be explained by nonadditive genetic effects. Statistically detectable additive and dominance genetic effects were observed in the most parsimonious model only when females were reared on the chickpea. The most parsimonious models on both rearing hosts suggested a contribution of negative additive additive epistasis to the divergence of oviposition preference between the P and C populations. This indicates a positive effect of epistasis on the performance of the second generations of hybrids.